patina
patina (pat"i*nȧ; It. pa"te*nȧ) , noun
[Italian, from Latin patina a dish, a pan, a kind of cake. Compare Paten.]
1.
A dish or plate of metal or earthenware; a patella.
2.
(Fine Arts) The color or incrustation which age gives to works of art; especially, the green rust which covers ancient bronzes, coins, and medals. — Fairholt